Recent electronic devices such as laptop personal computers (PCs), tablet PCs (also referred to as slate PCs), smart phones, high-performance audio players, personal digital assistants (PDAs) and so on have touch panels to operate the electronic devices through the touch of fingers or styluses to the touch panels. FIG. 1 is a perspective view showing a laptop PC 500 as one example of an electronic device. The laptop PC 500 includes a housing 502, a liquid crystal panel 504, a keyboard (not shown) and a touch pad 506. The housing 502 contains therein a central processing unit (CPU) 510, a graphics processing unit (GPU) 512, a touch pad controller 514 for controlling the touch pad 506, and a display controller 516 for controlling the liquid crystal panel 504.
The touch pad controller 514 is mounted on a mounting surface of the touch pad 506. The touch pad controller 514 controls and monitors a state of the touch pad 506 and determines a coordinate touched by a user. The touch pad controller 514 and the CPU 510 are interconnected via a first bus 522. Information on the presence of a touch contact by the user and the coordinate touched by the user are transmitted to the CPU 510 via the first bus 522.
For high-performance electronic devices such as the laptop PC 500 and so on, mounting a plurality of sensors such as an acceleration sensor 520a, a gyro sensor 520b, a geomagnetic sensor 520c and the like (hereinafter collectively referred to as a sensor group 520) on the devices is being progressed. The sensor group 520 may be connected to the CPU 510 via a second bus 524 different from the first bus 522.
With the configuration of FIG. 1, the sensor group 520 can be controlled to acquire information only while the CPU 510 is operating, but the sensor group 520 cannot be operated when the CPU 510 is in a standby state or a shut-down state. In other words, the CPU 510 is required to be activated to operate the sensor group 520, which may act as an obstacle for low power consumption.